Thanks, it doesn't make sense to me either.  There is no evidence of drilling or milling and no scope or other addition.

I forget the date but at one time serial numbers were not required.  This may not be an American made Krag.  I have another Springfield Krag so, yes, it is a 30-40 Krag and has been in the family for over 50 years.  As you know these were manufactured in Europe before they were here.  Pictures are a problem for me but I'll se if I can get some help there.